In packing units of known cartoning machines, each group of packets of cigarettes is fed to the loading station in a substantially radial direction with respect to the first wheel, and the relative blank is fed to the loading station in a direction tangent to the first wheel, is arrested in front of the relative first seat so as to close it, and is inserted inside the first seat by the relative group of packets. Similarly, each sheet of overwrapping material is fed to the transfer station in a direction substantially tangent to the first and second wheel, is arrested in front of the relative second seat so as to close it, and is inserted inside the second seat by the relative carton as this is expelled from the relative first seat into the relative second seat.
Though almost universally employed, the above packing method has several drawbacks, which increase in importance with the operating speed of the cartoning machine, and which are normally due to the difficulty encountered in controlling the position of the packing materials, as they are inserted inside the relative seats, in confined, mechanically crowded areas such as the loading and transfer stations, to which the packing materials are normally fed by gravity, and in which the blanks and sheets of overwrapping material constituting the packing materials are not normally clamped to position them accurately with respect to the relative groups as they are first inserted inside the relative seats, but are simply arrested against stops, with no possibility of preventing undesired slippage between the packing materials and the groups.
Moreover, being fed by gravity to the loading and transfer stations, the packing materials must be located over the packing units. This is not normally a problem in the case of sheets of overwrapping material, which are normally cut off massive reels, but is undoubtedly problematic in the case of blanks, which call for using an open-bottom hopper which must be fed continually with stacks of blanks.